1. Field of the Invention
The present invention, generally, relates to a system and method for the effective utilization of waste heat from cement kilns to produce usable forms of power.
More particularly, the present invention, generally, relates to a system and method for the effective utilization of waste heat from cement kilns to produce usable forms of power, where the system includes a cement plant CP, a heat exchange unit HEU having sequential heat exchanges stages for transferring heat from two heat source stream produced by the cement plant CP, and a power plant PP.
2. Description of the Related Art
Usually, cement kilns produce two streams of waste heat; a stream of flue gas and a stream of hot air. The flow rate of the flue gas is usually larger than the flow rate of the hot air. The initial temperature of the flue gas is higher than the initial temperature of the hot air. In a typical application of this sort, the stream of flue gas is returned to the kiln after it is partially cooled, where it is then used to pre-heat the raw materials used in cement production.
This type of system imposes a limit on the final temperature to which the flue gas can be cooled in a power system. The final temperature to which the flue gas can be cooled is substantially higher than the final temperature to which the stream of hot air can be cooled.
Thus, there is a need in the art for a more effective and efficient system and method for improved power extraction from cement kiln waste stream, which, because of the two waste stream have different temperature and different heat exchange characteristics, uses separate heat exchanger apparatuses, one for the flue gas and one for the hot air.